To mix the jello, follow the directions on the back of the box, but when the directions call for 2 cups of cold water, substitute the cold water with 2 cups of vanilla ice cream. Stir until ice cream is melted. Pour the jello mixture into a 9x13 dish and put in the freezer for 1/2 hour. Repeat the steps with the second box of jello. Pour gently over the mixture making sure you don't pour through the first layer. Put back in the freezer for another 1/2 hour. Repeat the steps with the final box and put the dish in the refrigerator for a minimum of 4 hours.